Saturday solicitation: What's something that has [truthfully] paid for itself?

Every Saturday, I’m going to post a question to my readers – and you’re free to answer in the comments in any way that you like. These questions are meant to spur discussion and, who knows, I might actually learn something from you fine people along the way.

Today's question is:

What's something that has [truthfully] paid for itself?

Comment below with your answer.